Hired as bodyguards to protect Sporadik, a Russian chess champion, during his match against a chess-playing computer called Nimrod, the Avengers are witness to him having a fatal heart attack. Taking on the guise of Dr. Donald Blake, Thor reports that Sporadik was poisoned and the Avengers soon learn that his chess pieces were coated with a poison that could be absorbed through the skin. That night, the man responsible, Leonard Tippit attempts to sneak out, after spending the day hiding inside the Nimrod computer. There he is confronted by the Vision who stayed behind to look for suspicious people. Tippit suddenly exhibits super-human powers and easily defeats the Vision but is soon discovered by Captain America who easily knocks him out, however, Tippit's powers allow his unconscious form to escape.

Recovering from the attack, the Avengers are suddenly jolted by a strange energy and are made privy to the origin of Tippit's super-powers: That two nights ago, Tippit was visited by the Watcher who had informed him of an impending nuclear holocaust that would destroy the entire human race. Giving Tippit vast cosmic power, the Watcher informs him that five individuals in the present would one-day birth children who would all play an important part in the end of the world in the future. Utatu tells Tippit that the only way to stop this impending doom is to kill all the parents of these future children. Although knowing their every thought and knowing that these are good people, Tippit eventually lives with his fate that he would have to kill these people so that he can save countless millions in the future.

With the trip into Tippit's past over, the Avengers decided that killing the innocent people would be wrong and determine the best course of action is to try and stop Tippit from reaching his goal. The Avengers then travel to the locations of each of the remaining five victims, but each time they arrive too late or are overpowered by Tippit's power and are unable to stop him from killing the remaining four victims. While this is occurring, Iron Man is also developing a device that would be able to immobilize Tippit.

With the last victim killed, the Scarlet Witch manages to stun Tippit with a hex bolt long enough for Iron Man to put the control helmet on Tippit. The Watcher arrives, and informs the Avengers that this was all a plot to stop Tippit -- the real menace -- and that the Watcher convinced him to go on his killing spree in order to alert the attention of the Avengers whom the Watcher hoped would find a way to subdue him. The ensuing battle weakened Tippit enough for the Watcher to capture him and take him away. Not wanting to an unimportant person in death as he was in life, he tells the Avengers that he wished he had one moment to be an important person. The Avengers promise to let him be known as the man who saved the world before he is whisked off by the Watcher, leaving the Avengers to ponder over the events of the past day.